Goldfinches are a welcome splash of color at our backyard feeders

Jun 13, 2023

Two pairs of pied-billed grebes nested and raised broods on Assawa Lake this season.

The small shallow lake behind my house is replete with broods of different species of waterfowl and other wetland-dependent birds — blue-winged teal, mallard, wood duck, hooded merganser, ring-billed duck, black tern, sandpipers and other shorebirds, and more.

The trumpeter swan pair, however, failed to raise their brood to fledgling stage. One by one their cygnets disappeared, victims of predation.

Pied-billed grebes are a curious and secretive species of waterfowl. During the summers of 1998 and 1999 when I conducted my master’s wildlife research project in the prairie potholes of North Dakota, I became very familiar with this bird’s behaviors, preferred habitat, and vocalizations.

My project included assessing the presence and absence of so-called secretive species of wild birds, which are birds characterized as those more often heard than observed.

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Early on in my relationship with pied-billed grebes, I noticed a peculiar, yet fascinating ability of the species. Obviously, adept at flying, swimming and diving, pied-billed grebes often can be observed in a semi-submerged posture on the surface of the water. Put another way, these little grebes have the unique talent of being able to sink, at will, as if they were an avian submarine about to dive.

Different than a mere dive, pied-billed grebes can compress their feathers to squeeze out excess air (loons do this, too), in addition to forcing air from its internal airs sacs, thus effectively making the bird less buoyant.

As a result, pied-billed grebes can swim extremely low in the water with their backs barely breaking the surface (or held just below) as their heads protrude slightly above the surface like a periscope while looking for danger. And, if necessary, pied-billed grebes can completely sink below the surface in a motion nearly undetectable.

Interestingly, the Latin name for grebe (Podilymbus podiceps), loosely means “feet at the buttocks.” Such a descriptor is appropriate since these birds and other related birds, loons included, have their feet situated near the rear end of their bodies.

Such a location enables a pied-billed grebe to dive and propel itself below the surface of the water with ease. And like other waterfowl with so-positioned feet, they are often observed skittering across the surface of water with wings flapping and churning feet on their long take-offs before becoming completely airborne.

Pied-billed grebes are common throughout Minnesota, especially in quiet wetlands with an abundance of emergent and submergent aquatic vegetation where concealment is readily available, including providing nesting habitat.

The chicken-like pied-billed grebe with its lobed toes and buoyancy-control mechanisms, makes these birds expert swimmers and divers well-suited to their environment. Its namesake “pied-billed” is in reference to its two-colored (pied), bluish-white bill and distinctive black bar marking on either side.

The carnivorous diet of pied-billed grebes consists of insects, minnows, amphibians, crabs, shrimp, snails, mussels, beetles, dragonfly nymphs, and leeches. Their strong and stout bills enable pied-billed grebes to easily capture and crush the bodies of prey.

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Indeed, while watching a female with her two chicks one day, swimming and feeding together on Assawa, I observed a parent capture a minnow and feed it to one of her chicks.

Mated pairs share in the duties of nest building, which is a modest bowl structure built above the water on a floating vegetative nest platform within the security of emergent vegetation. Constructed in about a day, the hen will lay anywhere from four to six eggs — one a day — followed by an incubation period of about 23 to 25 days.

Both grebe parents dutifully care for their chicks, and in fact, also like loons, pied-billed grebe chicks ride on each of their parents' backs during most of their first week of life.

The calls of pied-billed grebes are dissimilar to most other birds, too. Vocalizations are variable but are generally described as a long series of loon-like “ca-ow, ca-ow, ca-ow” notes that increase in volume and speed, culminating in another long series of “ka-ooo” notes.

Truly, there are few wild birds like the pied-billed grebe. Clearly heard, less often viewed — and the smallest of our Minnesota grebes—pied-billed grebes are easy to appreciate as we get out and enjoy the great outdoors.

Blane Klemek is a Minnesota DNR wildlife manager. He can be reached at [email protected].

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